Cell selection method and apparatus

Abstract

A cell selection method and an apparatus are provided. The method includes: performing, by a terminal, cell measurement; obtaining, by the terminal, cell selection auxiliary information; and performing, by the terminal, cell selection or cell reselection according to a cell measurement result and the cell selection auxiliary information. By using the method, the terminal can select a more suitable cell.

What is claimed is: 
     
       1. A cell selection method, comprising:
 performing, by a terminal, cell measurement; 
 obtaining from a base station, by the terminal, cell selection auxiliary information comprising carrier configuration characteristic information; and 
 performing, by the terminal, cell selection according to a cell measurement result and the cell selection auxiliary information; 
 wherein: 
 the carrier configuration characteristic information comprising:
 a carrier identifier and indication information corresponding to the carrier identifier, wherein the indication information is used to indicate whether a corresponding carrier is configured as a carrier used to avoid interference to a neighboring cell; 
 the carrier used to avoid interference to a neighboring cell comprises an extension carrier with a null subframe without a cell-specific reference signal (CRS) for an aggressor cell, which forms complete protection on a victim terminal in a victim cell, wherein the aggressor cell is an interfering cell and the victim cell is an interfered cell. 
 
 
     
     
       2. The method according to  claim 1 , wherein the performing, by the terminal, cell selection according to a cell measurement result and the cell selection auxiliary information comprises:
 determining, by the terminal, a candidate target set for the cell selection according to the cell measurement result, wherein the candidate target set comprises a candidate target cell or a candidate target base station; and 
 selecting, by the terminal, a cell from the candidate target set according to the cell selection auxiliary information. 
 
     
     
       3. The method according to  claim 1 , wherein the cell selection auxiliary information comprises one type or any combination of the following content:
 a carrier that is configured to be used to avoid interference to a neighboring cell is used as a high-priority cell selection target or a preferred resident carrier when the terminal has no cell-specific reference signal CRS interference suppression capability or interference cancellation capability; and 
 the carrier that is configured to be used to avoid interference to a neighboring cell is used as a low-priority cell selection target or a non-preferred resident carrier when the terminal has the CRS interference suppression capability or interference cancellation capability. 
 
     
     
       4. The method according to  claim 3 , wherein the selecting, by the terminal, a cell from the candidate target set according to the cell selection auxiliary information comprises:
 using a first carrier, configured on an interfered base station, as a high-priority cell selection target or a preferred resident carrier when the terminal has no CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises multiple carriers configured on the interfered base station, the multiple carriers have a highest priority, and the first carrier in the multiple carriers is configured by an interfering base station as a carrier used to avoid interference to a neighboring cell. 
 
     
     
       5. The method according to  claim 3 , wherein the selecting, by the terminal, a cell from the candidate target set according to the cell selection auxiliary information comprises:
 using the carrier, configured by an interfered base station, as a high-priority cell selection target or a preferred resident carrier when the terminal has no CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises a carrier configured on multiple mutually interfering base stations, and the carrier is configured by one or more interfering base stations in the multiple mutually interfering base stations as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations. 
 
     
     
       6. The method according to  claim 3 , wherein the selecting, by the terminal, a cell from the candidate target set according to the cell selection auxiliary information comprises:
 using a first carrier, configured on an interfered base station, as a low-priority cell selection target or a non-preferred resident carrier when the terminal has the CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises multiple carriers configured on the interfered base station, the multiple carriers have a highest priority, and the first carrier in the multiple carriers is configured by an interfering base station as a carrier used to avoid interference to a neighboring cell. 
 
     
     
       7. The method according to  claim 3 , wherein the selecting, by the terminal, a cell from the candidate target set according to the cell selection auxiliary information comprises:
 using the carrier, configured by an interfered base station, as a low-priority cell selection target or a non-preferred resident carrier when the terminal has the CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises a carrier configured on multiple mutually interfering base stations, and the carrier is configured by one or more interfering base stations in the multiple mutually interfering base stations as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations. 
 
     
     
       8. The method according to  claim 1 , further comprising:
 using a second carrier, configured by an interfered base station, as a high-priority cell selection target or a preferred resident carrier, wherein the second carrier is one of the N carriers, and a quantity of interfering base stations that configure the second carrier as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations is greater than a quantity of interfering base stations that configure another carrier in the N carriers as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations. 
 
     
     
       9. The method according to  claim 1 , further comprising:
 using a second carrier, configured by an interfered base station, as a low-priority cell selection target or a non-preferred resident carrier, wherein the second carrier is one of the N carriers, and a quantity of interfering base stations that configure the second carrier as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations is greater than a quantity of interfering base stations that configure another carrier in the N carriers as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations when the terminal has the CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises N carriers configured on multiple mutually interfering base stations, N is an integer greater than 1, and the N carriers are configured by one or more interfering base stations in the multiple mutually interfering base stations as carriers used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations. 
 
     
     
       10. The method according to  claim 1 , wherein the cell selection auxiliary information further comprises one type or a combination of the following information:
 a carrier with a specified characteristic; and 
 resident carrier preference information of the terminal. 
 
     
     
       11. The method according to  claim 10 , wherein the resident carrier preference information of the terminal comprises:
 an identifier of a carrier that is configured to be used to avoid interference to a neighboring cell and a list of a first terminal type and a list of a second terminal type that is corresponding to the identifier of the carrier, wherein 
 a terminal indicated by the first terminal type has no CRS interference suppression capability or interference cancellation capability, and uses a carrier that is configured to be used to avoid interference to a neighboring cell as a high-priority cell selection target; and 
 a terminal indicated by the second terminal type has the CRS interference suppression capability or interference cancellation capability, and uses a carrier that is configured to be used to avoid interference to a neighboring cell as a low-priority cell selection target. 
 
     
     
       12. A terminal, comprising:
 a processor; 
 a memory; 
 a transceiver; and 
 a bus interface, wherein the processor, the memory, and the transceiver are connected by using the bus interface, the memory stores data used when the processor performs an operation, the transceiver is configured to receive and transmit data under control of the processor, and 
 the processor is configured to read a program in the memory, to execute the following process: 
 performing cell measurement; 
 obtaining from a base station cell selection auxiliary information comprising carrier configuration characteristic information; and 
 performing cell selection according to a cell measurement result and the cell selection auxiliary information; 
 wherein: 
 the carrier configuration characteristic information comprising:
 a carrier identifier and indication information corresponding to the carrier identifier, wherein the indication information is used to indicate whether a corresponding carrier is configured as a carrier used to avoid interference to a neighboring cell; 
 the carrier used to avoid interference to a neighboring cell comprises an extension carrier with a null subframe without a cell-specific reference signal (CRS) for an aggressor cell, which forms complete protection on a victim terminal in a victim cell, wherein the aggressor cell is an interfering cell and the victim cell is an interfered cell. 
 
 
     
     
       13. The terminal according to  claim 12 , wherein the processor is specifically configured to:
 determine a candidate target set for the cell selection according to the cell measurement result, wherein the candidate target set comprises a candidate target cell or a candidate target base station; and 
 select a cell from the candidate target set according to the cell selection auxiliary information. 
 
     
     
       14. The terminal according to  claim 12 , wherein the cell selection auxiliary information comprises one type or any combination of the following content:
 a carrier that is configured to be used to avoid interference to a neighboring cell is used as a high-priority cell selection target or a preferred resident carrier when the terminal has no cell-specific reference signal CRS interference suppression capability or interference cancellation capability; and 
 the carrier that is configured to be used to avoid interference to a neighboring cell is used as a low-priority cell selection target or a non-preferred resident carrier when the terminal has one of the CRS interference suppression capability and interference cancellation capability. 
 
     
     
       15. The terminal according to  claim 14 , wherein the processor is configured to:
 use the first carrier, configured on the interfered base station, as a high-priority cell selection target or a preferred resident carrier when the terminal has no CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises multiple carriers configured on an interfered base station, the multiple carriers have a highest priority, and a first carrier in the multiple carriers is configured by an interfering base station as a carrier used to avoid interference to a neighboring cell. 
 
     
     
       16. The terminal according to  claim 14 , wherein the processor is configured to:
 use the carrier, configured by the interfered base station, as a high-priority cell selection or target or a preferred resident carrier when the terminal has no CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises a carrier configured on multiple mutually interfering base stations, and the carrier is configured by one or more interfering base stations in the multiple mutually interfering base stations as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations. 
 
     
     
       17. The terminal according to  claim 14 , wherein the processor is configured to:
 use the first carrier, configured on the interfered base station, as a low-priority cell selection target or a non-preferred resident carrier when the terminal has the CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises multiple carriers configured on an interfered base station, the multiple carriers have a highest priority, and a first carrier in the multiple carriers is configured by an interfering base station as a carrier used to avoid interference to a neighboring cell. 
 
     
     
       18. The terminal according to  claim 14 , wherein the processor is configured to:
 use the carrier, configured by the interfered base station, as a low-priority cell selection target or a non-preferred resident carrier when the terminal has the CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises a carrier configured on multiple mutually interfering base stations, and the carrier is configured by one or more interfering base stations in the multiple mutually interfering base stations as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations. 
 
     
     
       19. The terminal according to  claim 12 , wherein the processor is further configured to:
 use a second carrier, configured by the interfered base station, as a high-priority cell selection target or a preferred resident carrier, wherein the second carrier is one of the N carriers, and a quantity of interfering base stations that configure the second carrier as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations is greater than a quantity of interfering base stations that configure another carrier in the N carriers as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations when the terminal has no CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises N carriers configured on multiple mutually interfering base stations, N is an integer greater than 1, and the N carriers are configured by one or more interfering base stations in the multiple mutually interfering base stations as carriers used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations. 
 
     
     
       20. The terminal according to  claim 12 , wherein the processor is further configured to:
 use a second carrier, configured by the interfered base station, as a low-priority cell selection target or a non-preferred resident carrier, wherein the second carrier is one of the N carriers, and a quantity of interfering base stations that configure the second carrier as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations is greater than a quantity of interfering base stations that configure another carrier in the N carriers as a carrier used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations when the terminal has the CRS interference suppression capability or interference cancellation capability, the candidate target set determined by the terminal comprises N carriers configured on multiple mutually interfering base stations, N is an integer greater than 1, and the N carriers are configured by one or more interfering base stations in the multiple mutually interfering base stations as carriers used to avoid interference to one or more interfered neighboring cells of the multiple mutually interfering base stations.